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1
/*
2
 *  MIPS emulation helpers for qemu.
3
 * 
4
 *  Copyright (c) 2004-2005 Jocelyn Mayer
5
 *
6
 * This library is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
10
 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14
 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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#include <stdarg.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <inttypes.h>
25
#include <signal.h>
26
#include <assert.h>
27

    
28
#include "cpu.h"
29
#include "exec-all.h"
30

    
31
enum {
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    TLBRET_DIRTY = -4,
33
    TLBRET_INVALID = -3,
34
    TLBRET_NOMATCH = -2,
35
    TLBRET_BADADDR = -1,
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    TLBRET_MATCH = 0
37
};
38

    
39
/* MIPS32 4K MMU emulation */
40
#ifdef MIPS_USES_R4K_TLB
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static int map_address (CPUState *env, target_ulong *physical, int *prot,
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                        target_ulong address, int rw, int access_type)
43
{
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    uint8_t ASID = env->CP0_EntryHi & 0xFF;
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    int i;
46

    
47
    for (i = 0; i < env->tlb_in_use; i++) {
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        tlb_t *tlb = &env->tlb[i];
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        /* 1k pages are not supported. */
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        target_ulong mask = tlb->PageMask | 0x1FFF;
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        target_ulong tag = address & ~mask;
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        int n;
53

    
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        /* Check ASID, virtual page number & size */
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        if ((tlb->G == 1 || tlb->ASID == ASID) &&
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            tlb->VPN == tag) {
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            /* TLB match */
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            n = !!(address & mask & ~(mask >> 1));
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            /* Check access rights */
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           if (!(n ? tlb->V1 : tlb->V0))
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                return TLBRET_INVALID;
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           if (rw == 0 || (n ? tlb->D1 : tlb->D0)) {
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                *physical = tlb->PFN[n] | (address & (mask >> 1));
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                *prot = PAGE_READ;
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                if (n ? tlb->D1 : tlb->D0)
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                    *prot |= PAGE_WRITE;
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                return TLBRET_MATCH;
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            }
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            return TLBRET_DIRTY;
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        }
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    }
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    return TLBRET_NOMATCH;
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}
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#endif
75

    
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static int get_physical_address (CPUState *env, target_ulong *physical,
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                                int *prot, target_ulong address,
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                                int rw, int access_type)
79
{
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    /* User mode can only access useg */
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    int user_mode = (env->hflags & MIPS_HFLAG_MODE) == MIPS_HFLAG_UM;
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    int ret = TLBRET_MATCH;
83

    
84
#if 0
85
    if (logfile) {
86
        fprintf(logfile, "user mode %d h %08x\n",
87
                user_mode, env->hflags);
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    }
89
#endif
90
    if (user_mode && address > 0x7FFFFFFFUL)
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        return TLBRET_BADADDR;
92
    if (address < (int32_t)0x80000000UL) {
93
        if (!(env->hflags & MIPS_HFLAG_ERL)) {
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#ifdef MIPS_USES_R4K_TLB
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            ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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            *physical = address + 0x40000000UL;
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            *prot = PAGE_READ | PAGE_WRITE;
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#endif
100
        } else {
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            *physical = address;
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            *prot = PAGE_READ | PAGE_WRITE;
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        }
104
    } else if (address < (int32_t)0xA0000000UL) {
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        /* kseg0 */
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        /* XXX: check supervisor mode */
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        *physical = address - (int32_t)0x80000000UL;
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        *prot = PAGE_READ | PAGE_WRITE;
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    } else if (address < (int32_t)0xC0000000UL) {
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        /* kseg1 */
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        /* XXX: check supervisor mode */
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        *physical = address - (int32_t)0xA0000000UL;
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        *prot = PAGE_READ | PAGE_WRITE;
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    } else if (address < (int32_t)0xE0000000UL) {
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        /* kseg2 */
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#ifdef MIPS_USES_R4K_TLB
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        ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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        *physical = address;
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        *prot = PAGE_READ | PAGE_WRITE;
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#endif
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    } else {
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        /* kseg3 */
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        /* XXX: check supervisor mode */
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        /* XXX: debug segment is not emulated */
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#ifdef MIPS_USES_R4K_TLB
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        ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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        *physical = address;
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        *prot = PAGE_READ | PAGE_WRITE;
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#endif
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    }
133
#if 0
134
    if (logfile) {
135
        fprintf(logfile, TLSZ " %d %d => " TLSZ " %d (%d)\n",
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                address, rw, access_type, *physical, *prot, ret);
137
    }
138
#endif
139

    
140
    return ret;
141
}
142

    
143
#if defined(CONFIG_USER_ONLY) 
144
target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
145
{
146
    return addr;
147
}
148
#else
149
target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
150
{
151
    target_ulong phys_addr;
152
    int prot;
153

    
154
    if (get_physical_address(env, &phys_addr, &prot, addr, 0, ACCESS_INT) != 0)
155
        return -1;
156
    return phys_addr;
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}
158

    
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void cpu_mips_init_mmu (CPUState *env)
160
{
161
}
162
#endif /* !defined(CONFIG_USER_ONLY) */
163

    
164
int cpu_mips_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
165
                               int is_user, int is_softmmu)
166
{
167
    target_ulong physical;
168
    int prot;
169
    int exception = 0, error_code = 0;
170
    int access_type;
171
    int ret = 0;
172

    
173
    if (logfile) {
174
#if 0
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        cpu_dump_state(env, logfile, fprintf, 0);
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#endif
177
        fprintf(logfile, "%s pc " TLSZ " ad " TLSZ " rw %d is_user %d smmu %d\n",
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                __func__, env->PC, address, rw, is_user, is_softmmu);
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    }
180

    
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    rw &= 1;
182

    
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    /* data access */
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    /* XXX: put correct access by using cpu_restore_state()
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       correctly */
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    access_type = ACCESS_INT;
187
    if (env->user_mode_only) {
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        /* user mode only emulation */
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        ret = TLBRET_NOMATCH;
190
        goto do_fault;
191
    }
192
    ret = get_physical_address(env, &physical, &prot,
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                               address, rw, access_type);
194
    if (logfile) {
195
        fprintf(logfile, "%s address=" TLSZ " ret %d physical " TLSZ " prot %d\n",
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                __func__, address, ret, physical, prot);
197
    }
198
    if (ret == TLBRET_MATCH) {
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       ret = tlb_set_page(env, address & TARGET_PAGE_MASK,
200
                          physical & TARGET_PAGE_MASK, prot,
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                          is_user, is_softmmu);
202
    } else if (ret < 0) {
203
    do_fault:
204
        switch (ret) {
205
        default:
206
        case TLBRET_BADADDR:
207
            /* Reference to kernel address from user mode or supervisor mode */
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            /* Reference to supervisor address from user mode */
209
            if (rw)
210
                exception = EXCP_AdES;
211
            else
212
                exception = EXCP_AdEL;
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            break;
214
        case TLBRET_NOMATCH:
215
            /* No TLB match for a mapped address */
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            if (rw)
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                exception = EXCP_TLBS;
218
            else
219
                exception = EXCP_TLBL;
220
            error_code = 1;
221
            break;
222
        case TLBRET_INVALID:
223
            /* TLB match with no valid bit */
224
            if (rw)
225
                exception = EXCP_TLBS;
226
            else
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                exception = EXCP_TLBL;
228
            break;
229
        case TLBRET_DIRTY:
230
            /* TLB match but 'D' bit is cleared */
231
            exception = EXCP_LTLBL;
232
            break;
233
                
234
        }
235
        /* Raise exception */
236
        env->CP0_BadVAddr = address;
237
        env->CP0_Context = (env->CP0_Context & 0xff800000) |
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                           ((address >> 9) &   0x007ffff0);
239
        env->CP0_EntryHi =
240
            (env->CP0_EntryHi & 0xFF) | (address & (TARGET_PAGE_MASK << 1));
241
        env->exception_index = exception;
242
        env->error_code = error_code;
243
        ret = 1;
244
    }
245

    
246
    return ret;
247
}
248

    
249
#if defined(CONFIG_USER_ONLY)
250
void do_interrupt (CPUState *env)
251
{
252
    env->exception_index = EXCP_NONE;
253
}
254
#else
255
void do_interrupt (CPUState *env)
256
{
257
    target_ulong offset;
258
    int cause = -1;
259

    
260
    if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
261
        fprintf(logfile, "%s enter: PC " TLSZ " EPC " TLSZ " cause %d excp %d\n",
262
                __func__, env->PC, env->CP0_EPC, cause, env->exception_index);
263
    }
264
    if (env->exception_index == EXCP_EXT_INTERRUPT &&
265
        (env->hflags & MIPS_HFLAG_DM))
266
        env->exception_index = EXCP_DINT;
267
    offset = 0x180;
268
    switch (env->exception_index) {
269
    case EXCP_DSS:
270
        env->CP0_Debug |= 1 << CP0DB_DSS;
271
        /* Debug single step cannot be raised inside a delay slot and
272
         * resume will always occur on the next instruction
273
         * (but we assume the pc has always been updated during
274
         *  code translation).
275
         */
276
        env->CP0_DEPC = env->PC;
277
        goto enter_debug_mode;
278
    case EXCP_DINT:
279
        env->CP0_Debug |= 1 << CP0DB_DINT;
280
        goto set_DEPC;
281
    case EXCP_DIB:
282
        env->CP0_Debug |= 1 << CP0DB_DIB;
283
        goto set_DEPC;
284
    case EXCP_DBp:
285
        env->CP0_Debug |= 1 << CP0DB_DBp;
286
        goto set_DEPC;
287
    case EXCP_DDBS:
288
        env->CP0_Debug |= 1 << CP0DB_DDBS;
289
        goto set_DEPC;
290
    case EXCP_DDBL:
291
        env->CP0_Debug |= 1 << CP0DB_DDBL;
292
        goto set_DEPC;
293
    set_DEPC:
294
        if (env->hflags & MIPS_HFLAG_BMASK) {
295
            /* If the exception was raised from a delay slot,
296
               come back to the jump.  */
297
            env->CP0_DEPC = env->PC - 4;
298
            env->hflags &= ~MIPS_HFLAG_BMASK;
299
        } else {
300
            env->CP0_DEPC = env->PC;
301
        }
302
    enter_debug_mode:
303
        env->hflags |= MIPS_HFLAG_DM;
304
        /* EJTAG probe trap enable is not implemented... */
305
        env->PC = (int32_t)0xBFC00480;
306
        break;
307
    case EXCP_RESET:
308
        cpu_reset(env);
309
        break;
310
    case EXCP_SRESET:
311
        env->CP0_Status = (1 << CP0St_SR);
312
        env->CP0_WatchLo = 0;
313
        goto set_error_EPC;
314
    case EXCP_NMI:
315
        env->CP0_Status = (1 << CP0St_NMI);
316
    set_error_EPC:
317
        if (env->hflags & MIPS_HFLAG_BMASK) {
318
            /* If the exception was raised from a delay slot,
319
               come back to the jump.  */
320
            env->CP0_ErrorEPC = env->PC - 4;
321
            env->hflags &= ~MIPS_HFLAG_BMASK;
322
        } else {
323
            env->CP0_ErrorEPC = env->PC;
324
        }
325
        env->hflags |= MIPS_HFLAG_ERL;
326
        env->CP0_Status |= (1 << CP0St_ERL) | (1 << CP0St_BEV);
327
        env->PC = (int32_t)0xBFC00000;
328
        break;
329
    case EXCP_MCHECK:
330
        cause = 24;
331
        goto set_EPC;
332
    case EXCP_EXT_INTERRUPT:
333
        cause = 0;
334
        if (env->CP0_Cause & (1 << CP0Ca_IV))
335
            offset = 0x200;
336
        goto set_EPC;
337
    case EXCP_DWATCH:
338
        cause = 23;
339
        /* XXX: TODO: manage defered watch exceptions */
340
        goto set_EPC;
341
    case EXCP_AdEL:
342
    case EXCP_AdES:
343
        cause = 4;
344
        goto set_EPC;
345
    case EXCP_TLBL:
346
        cause = 2;
347
        if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
348
            offset = 0x000;
349
        goto set_EPC;
350
    case EXCP_IBE:
351
        cause = 6;
352
        goto set_EPC;
353
    case EXCP_DBE:
354
        cause = 7;
355
        goto set_EPC;
356
    case EXCP_SYSCALL:
357
        cause = 8;
358
        goto set_EPC;
359
    case EXCP_BREAK:
360
        cause = 9;
361
        goto set_EPC;
362
    case EXCP_RI:
363
        cause = 10;
364
        goto set_EPC;
365
    case EXCP_CpU:
366
        cause = 11;
367
        env->CP0_Cause = (env->CP0_Cause & ~0x03000000) | (env->error_code << 28);
368
        goto set_EPC;
369
    case EXCP_OVERFLOW:
370
        cause = 12;
371
        goto set_EPC;
372
    case EXCP_TRAP:
373
        cause = 13;
374
        goto set_EPC;
375
    case EXCP_LTLBL:
376
        cause = 1;
377
        goto set_EPC;
378
    case EXCP_TLBS:
379
        cause = 3;
380
        if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
381
            offset = 0x000;
382
        goto set_EPC;
383
    set_EPC:
384
        if (env->hflags & MIPS_HFLAG_BMASK) {
385
            /* If the exception was raised from a delay slot,
386
               come back to the jump.  */
387
            env->CP0_EPC = env->PC - 4;
388
            env->CP0_Cause |= 0x80000000;
389
            env->hflags &= ~MIPS_HFLAG_BMASK;
390
        } else {
391
            env->CP0_EPC = env->PC;
392
            env->CP0_Cause &= ~0x80000000;
393
        }
394
        if (env->CP0_Status & (1 << CP0St_BEV)) {
395
            env->PC = (int32_t)0xBFC00200;
396
        } else {
397
            env->PC = (int32_t)0x80000000;
398
        }
399
        env->hflags |= MIPS_HFLAG_EXL;
400
        env->CP0_Status |= (1 << CP0St_EXL);
401
        env->PC += offset;
402
        env->CP0_Cause = (env->CP0_Cause & ~0x7C) | (cause << 2);
403
        break;
404
    default:
405
        if (logfile) {
406
            fprintf(logfile, "Invalid MIPS exception %d. Exiting\n",
407
                    env->exception_index);
408
        }
409
        printf("Invalid MIPS exception %d. Exiting\n", env->exception_index);
410
        exit(1);
411
    }
412
    if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
413
        fprintf(logfile, "%s: PC " TLSZ " EPC " TLSZ " cause %d excp %d\n"
414
                "    S %08x C %08x A " TLSZ " D " TLSZ "\n",
415
                __func__, env->PC, env->CP0_EPC, cause, env->exception_index,
416
                env->CP0_Status, env->CP0_Cause, env->CP0_BadVAddr,
417
                env->CP0_DEPC);
418
    }
419
    env->exception_index = EXCP_NONE;
420
}
421
#endif /* !defined(CONFIG_USER_ONLY) */
422

    
423
void invalidate_tlb (CPUState *env, int idx, int use_extra)
424
{
425
    tlb_t *tlb;
426
    target_ulong addr;
427
    target_ulong end;
428
    uint8_t ASID = env->CP0_EntryHi & 0xFF;
429
    target_ulong mask;
430

    
431
    tlb = &env->tlb[idx];
432
    /* The qemu TLB is flushed then the ASID changes, so no need to
433
       flush these entries again.  */
434
    if (tlb->G == 0 && tlb->ASID != ASID) {
435
        return;
436
    }
437

    
438
    if (use_extra && env->tlb_in_use < MIPS_TLB_MAX) {
439
        /* For tlbwr, we can shadow the discarded entry into
440
           a new (fake) TLB entry, as long as the guest can not
441
           tell that it's there.  */
442
        env->tlb[env->tlb_in_use] = *tlb;
443
        env->tlb_in_use++;
444
        return;
445
    }
446

    
447
    /* 1k pages are not supported. */
448
    mask = tlb->PageMask | 0x1FFF;
449
    if (tlb->V0) {
450
        addr = tlb->VPN;
451
        end = addr | (mask >> 1);
452
        while (addr < end) {
453
            tlb_flush_page (env, addr);
454
            addr += TARGET_PAGE_SIZE;
455
        }
456
    }
457
    if (tlb->V1) {
458
        addr = tlb->VPN | ((mask >> 1) + 1);
459
        addr = tlb->VPN + TARGET_PAGE_SIZE;
460
        end = addr | mask;
461
        while (addr < end) {
462
            tlb_flush_page (env, addr);
463
            addr += TARGET_PAGE_SIZE;
464
        }
465
    }
466
}